Papers by Lucas Travassos
Informática na educação: teoria & prática
Na perspectiva da Tecnologia Assistiva e de sua aplicação no contexto da Comunicação Alternativa,... more Na perspectiva da Tecnologia Assistiva e de sua aplicação no contexto da Comunicação Alternativa, os jogos digitais podem ser produzidos e aplicados em atividades lúdicas junto às crianças com transtorno severo da fala com o intuito de ampliar a comunicação e, consequentemente, contribuir para a promoção do desenvolvimento infantil. Diante desses pressupostos, este trabalho tem por objetivo analisar a frequência de ocorrência das diferentes formas de comunicação de crianças com Paralisia Cerebral sem oralidade durante atividades com jogos digitais. Participaram desta pesquisa quatro crianças com Paralisia Cerebral, sendo três do sexo masculino e uma do sexo feminino com idades entre 7 e 12 anos. Todas as crianças apresentaram severos distúrbios na comunicação oral. Atentos às necessidades das crianças, três jogos digitais foram desenvolvidos para essa população: Alimentação, Segurança Pública e Cidade Sustentável. As atividades com os três jogos digitais ocorreram em 5 sessões, com ...
IEEE Transactions on Magnetics
International Journal of Automotive Technology
Industrial organizations have increasingly sought to optimize the resources needed for the manufa... more Industrial organizations have increasingly sought to optimize the resources needed for the manufacture of its products from the competition, in order to maintain their profit margins. The search for balance of resources and balanced distribution of tasks in various types of industrial environments is called balancing. When adjustments are made and adequacy of an assembly line that is already in operation, this process is called rebalancing. This paper presents a case study involving a problem of rebalancing of automotive assembly line in an environment of arbitrarily mixed models of products, also known as mix. The proposed procedure for solving the rebalancing in the company in question is based on Binary Integer Programming, in particular the branch and bound algorithm. For comparison, we used a heuristic method based on precedence diagrams for solving the rebalancing of lines. To evaluate the results obtained between the two procedures were used performance indicators such as number of workstations created, average load of work and level of unbalance. The proposed algorithm has resulted in significant improvements in the production line capacity.
The European Conference on Antennas and Propagation Eucap 2006, Oct 1, 2006
Revista Virtual De Quimica, Nov 12, 2013
Avaliação: Revista da Avaliação da Educação Superior (Campinas), 2016
Resumo Este artigo tem como objetivo apresentar uma análise realizada sobre o nível de implantaçã... more Resumo Este artigo tem como objetivo apresentar uma análise realizada sobre o nível de implantação do processo de autoavaliação nas faculdades privadas de Salvador na visão dos coordenadores da CPA. Para tanto, realizou-se uma pesquisa com 14 faculdades privadas de Salvador, utilizando como instrumento de coleta de dados, o questionário, com questões mistas (fechadas e abertas). As conclusões indicam que menos da metade das faculdades analisadas possui o processo de autoavaliação implantado de forma suficiente, ou seja, atendendo aos requisitos mínimos exigidos pelo INEP.
Http Www Theses Fr, 2007
Je remercie vivement Monsieur Laurent Nicolas, directeur du laboratoire Ampère, de m'avoir accuei... more Je remercie vivement Monsieur Laurent Nicolas, directeur du laboratoire Ampère, de m'avoir accueilli au sein de son equipe. Je tiensà remercier les personnes qui m'ont orienté : • Monsieur A. Nicolas pour la qualité de l'encadrement dont j'ai pu bénéficier tout au long de ce travail et pour toute sa confiance et son soutien inconditionnel dans mes décisions. • Monsieur Christian Vollaire pour la qualité de ses relations humaines durant ces années me faisant grandement bénéficier de son expérience et de ses compétences. • Monsieur Nathan Ida pour m'avoir accueilli pendant mon séjour a The University of Akron. Qu'il trouve ici l'expression de ma profonde reconnaissance par ses qualités humaines, scientifiques et pour son extrême disponibilité. Que Monsieur J-L. Coulomb et Monsieur D. Lesselier, soient ici remerciés de l'honneur qu'ils me font en jugeant ce travail. Monsieur J. P. Bastos, de la même manière, mérite une mention spéciale pour avoir accepte sans hésiter d'être rapporteur de mon travail de thèse de doctorat. Je tiensà remercier aussi les professeurs,élèves et personnel du ECL et UA, pour m'avoir accueilli dans la plénitude de mes expectatives pendant mon séjour en France et aux Etats-Unis. Je voudrais remercier tout particulièrement Monsieur Philippe Billoux, assistant de direction, pour son aide, patience et conseils pour la vie quotidienne en France. Je ne saurais oublier Monsieur Ronan Perrussel pour toutes ses précieuses contributions pour ce travail pendant presque trois années. Qu'il sache que je serais toujours reconnaissant pour la qualité remarquable de ses commentaires dont il m'a fait bénéficier mais aussi pour sa patience, sa disponibilité et sa bonne humeur. Finalement, je tiensà remercier vivement mes parents qui ont su m'apporter tout leur soutien, leurs pensées, leurs prières et leur amourà distance maisà tout instant. vi 0. Remerciements 0.2. Scope and contribution of the present work ix • To model the process of a radar testing system using numerical methods. This modeling code will be used to study the radar wave propagation in a dispersive medium using the reflected wave from different types of concrete structures and different inclusions. • To optimize the modeling process by improvements in the absorbing boundary condition, and • To implement imaging algorithms which should be capable to detect faults given a radar reflected signal. 0.2 Scope and contribution of the present work In the present study, it is proposed to implement electromagnetic wave propagation models in concrete structures using various numerical techniques to investigate the different aspects of GPR, or simply, radar inspection of concrete. First, a 3D Finite-Difference Time-Domain (FDTD) algorithm was implemented for the simulation of concrete structures which allows modeling of characteristics such as porosty, salt content and degree of saturation of the mixture using Debye parameters. Next, a novel optimization algorithm for the improvement of bowtie antennas for closely spaced targets using Genetic Algorithms and the Moment Method (MoM) is proposed. Finally, parametric and non-parametric imaging algorithms were implemented, to obtain fast and accurate estimation of target shapes under some constraints in inhomogeneous media using a Migration Algorithm, Particle Swarm Optimization and Neural Networks. The performance of the proposed algorithms are confirmed by numerical simulations. Chapter 1 presents a brief discussion about the most commonly used NDT techniques for concrete. Operation principles, advantages and drawbacks of each technique are outlined. This chapter ends with a discussion of the needs of numerical modeling for NDT. Chapter 2 reviews the electromagnetic basic equations to simulate the radar assessment of concrete structures and the most commonly used numerical techniques to model the interaction field-defect. The main algorithm using the FDTD method has been verified with measurements of a microstrip antenna and a Transmission Line Matrix (TLM) algorithm implemented by the candidate. Detailed derivation has been included where necessary and references are given where material is drawn from outside sources. The implementation and coding of a radar simulator in a dispersive environment is the candidate's own original work. In addition an optimal configuration for Perfectly Matched Layers (PML) is proposed [3] using a theorethical approach and both the mono-objective genetic algorithm (GA) and multiobjective genetic algorithm (MGA), which is a novel approach. Chapter 3 reviews the radar systems available at present and discusses the relevant antenna constraints with particular emphasis on amplitude-modulated signals. Although most of the topics discussed in this chapter are in no sense novel, this chapter provides a good overview of the fundamental aspects of radar assessment. In addition, a procedure to improve the radiation pattern of bowtie antennas is presented [4]. This procedure seeks to achieve two objectives: to minimize the metal area of the antenna (in order to reduce the size and weight) and to maximize the gain in the plane perpendicular to the antenna. This approach involves the Moment Method (MoM) in conjunction with the MGA. Finally, a study of the dispersion from heterogeneous dielectrics is shown. Chapter 4 presents the imaging algorithms used to classify the targets. First, the Reverse-Time Migration Algorithm is implemented in order to detect buried inclusions in the presence of noise and heterogeneity. Next, a model fitting approach is shown using Particle Swarm Optimization (PSO) in order to reduce the computational cost of non-linear inverse problems. Finally, Artificial Neural Networks (ANN) are used to improve the detection of buried cylinders using the Parallel Layer Perceptron (PLP) Architecture. A new approach [5] using PLP and Principal Component Analyis (PCA) is proposed to compress the radar data in order to train ANN faster. To the candidate's best knowledge, the application of PCA to reduce the order of the data in ANN trainning in the context of radar assessment in concrete environment is also a novel approach. Chapter 5 summarises the work and provides recommendations for future research. x 0. Introduction 1. NDT techniques for concrete structures
Applied Computational Electromagnetics Society Journal
This paper presents a numerical procedure to calculate the time-domain response of thin-wire ante... more This paper presents a numerical procedure to calculate the time-domain response of thin-wire antennas over Debye media. The method is based in an expansion of the electricfield integral-equation in the time-domain (EFIE-TD), which accounts for the Debye media by using a reflection-coefficient approach. Resulting extended integral equation is subsequently solved by the method of moments. Numerical examples including Debye soils show not only the accuracy of the method but also a higher computational efficiency in comparison with other hybrid numerical techniques. Index Terms ─ Reflection coefficient approximation, time-domain integral equation, thin-wire antennas.
Revista de Administração Contemporânea, 2015
In the pharmaceutical industry, value is being destroyed through longer product development times... more In the pharmaceutical industry, value is being destroyed through longer product development times. Given that patent lives are (normally) fixed at 20 years, the double hit of increasing time to market is evident - higher R & D costs and less time at market before generic competitors are able to be released into the marketplace. The Policy implications are massive: A huge and permanent shift away from internal R & D towards partnerships, licensing deals and acquisitions of more innovative biotechnology companies. In this study, we build a system dynamics model of the product development pipeline for a single company operating in the pharmaceutical market. The study shows that in the presence of loss of value due to longer lead times, it is more advantageous to: (a) work faster to reduce the backlog of projects; (b) increase the number of projects started whenever it is possible reduce complexity in the pipeline; and also (c) the optimal decision on resource allocation is independent ...
The purpose of this study is to describe a methodology to assess the financial viability of radio... more The purpose of this study is to describe a methodology to assess the financial viability of radio frequency identification (RFID) applications and the main contributions of this technology. The impact of RFID technology on supply chain processes was assessed using an Internal Rate of Return analysis. An extensive, six-month discussion and refinement process with the logistics and supply chain managers of the company under study was conducted to validate the procedure and to collect the necessary data. Such technology enables inventory control, tracking of parts/products and customer satisfaction. The viability of using RFID technology for inventory control and product tracking was confirmed. Among the benefits obtained: the reduction of one worker from the inventory team, reduction in the costs for replacing a component and reduction in the costs incurred with defective components were found. This is one of the few attempts to quantify RFDI technology’s contribution.
Journal of Information Systems and Technology Management, 2014
This paper presents a methodology for the integration of RFID technology into microcomputer assem... more This paper presents a methodology for the integration of RFID technology into microcomputer assembly companies. Such a technology enables inventory control, tracking of parts/products and customer satisfaction. The methodology was developed to identify and evaluate the production process in an assembly company and to apply the process FMEA to evaluate potential faults and propose improvement actions for the use of RFID technology. The methodology was validated in a company from the Pólo de Informática de Ilhéus/BA. In this study, the viability of RFID technology for inventory control and traceability of the product was confirmed. Among the benefits obtained were the reduction of one of the workers from the inventory team, reduction in the costs of substituting a component, and reduction in lead-time.
Neurocomputing, 2015
ABSTRACT This paper presents a prediction algorithm for features detection in Ground Penetrating ... more ABSTRACT This paper presents a prediction algorithm for features detection in Ground Penetrating Radar (GPR) based surveys. Based on signal processing and soft-computing techniques, the coupled use of principal-component analysis and neural networks enables a definition of an efficient method for analyzing GPR electromagnetic data. To guarantee a low error rate, a study of the algorithm main numerical parameters was performed by means of electromagnetic synthetic-data models. Results for detecting features of geological layers demonstrate not only the method predictions accuracy but also the simple interpretation of its output through scenarios reconstructed images.
SAE Technical Paper Series, 2011
ABSTRACT Concrete is the most common building material and accounts for a large part of the syste... more ABSTRACT Concrete is the most common building material and accounts for a large part of the systems that are necessary for a country to operate smoothly including buildings, roads, and bridges. Nondestructive testing is one of the techniques that can be used to assess the structural condition. It provides nonperceptible information that conventional techniques of evaluation unable to do. The main objective of this work is the numerical simulation of a particular technique of nondestructive testing: the radar. The numerical modeling of the radar assessment of concrete structures make it possible to envisage the behavior of the system and its capacity to detect defects in various configurations. To achieve this objective, it was implemented electromagnetic wave propagation models in concrete structures, by using various numerical techniques to examine different aspects of the radar inspection. First of all, we implemented the finite-difference time-domain method in 3D which allows to take into account concrete characteristics such as porosity, salt content and the degree of saturation of the mixture by using Debye models. In addition, a procedure to improve the radiation pattern of bowtie antennas is presented. This approach involves the Moment Method in conjunction with the Multiobjective Genetic Algorithm. Finally, we implemented imaging algorithms which can perform fast and precise characterization of buried targets in inhomogenous medium by using three different methods. The performance of the proposed algorithms is confirmed by numerical simulations.
12th Biennial IEEE Conference on Electromagnetic Field Computation, CEFC 2006, 2006
In order to resolve closely spaced targets in a planar surface normal to the beam, the antenna us... more In order to resolve closely spaced targets in a planar surface normal to the beam, the antenna used in the radar assessment of concrete structures should have a narrow beam width which means a higher directivity. This work presents a procedure to optimize the field pattern of a bow-tie antenna using multi-objective genetic algorithms in conjunction with a MoM direct
Proceedings - International Conference on Tools with Artificial Intelligence, ICTAI, 2008
This paper applies a neural networks (NN) multiobjective learning algorithm called the Minimum Gr... more This paper applies a neural networks (NN) multiobjective learning algorithm called the Minimum Gradient Method (MGM) to filter noise in regression problems. This method is based on the concept that the learning is a bi-objective problem aiming at minimizing the empirical risk (training error) and the function complexity. The complexity is modeled as the norm of the network output gradient.
Digests of the 2010 14th Biennial IEEE Conference on Electromagnetic Field Computation, CEFC 2010, 2010
ABSTRACT This paper presents optimization problem formulations to design meander-line antennas fo... more ABSTRACT This paper presents optimization problem formulations to design meander-line antennas for passive radio frequency identification tags based on given specifications of input impedance, frequency range and geometric constraints. In this application, there is a need for directive transponders to select properly the target tag, which must be ideally isotropic. The design of an effective meander-line antenna for RFID purposes requires balancing geometrical characteristics with the microchip impedance. Therefore, there is an issue of optimization in determining the antenna parameters for best performance. The antenna is analysed by a method of moments. Some results using a deterministic optimization algorithm are shown.
Proceedings - 2012 11th International Conference on Machine Learning and Applications, ICMLA 2012, 2012
ABSTRACT Ground Penetrating Radar systems have been successfully used to access concrete structur... more ABSTRACT Ground Penetrating Radar systems have been successfully used to access concrete structures conditions. Moreover, inclusions in concrete can be discriminated by simple models based on traces obtained by GPR. In this work, concrete blocks with different inclusions were probed in controlled conditions. Some features were extracted from Ascans of this experimental data set. To get efficient models, raw data were submitted to features selection and space reduction methods. Without complex data pre-processing, good accuracy and more explainable models with less computational burden were obtained.
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Papers by Lucas Travassos